The invention relates to a protective, hollow, elongated housing, known in the industry as a curb box, which extends generally from a utility supply valve for a water or gas line buried in the ground, the curb box extending upwardly to the ground surface.
Gas or water mains, which supply residential or commercial buildings and which extend along and are buried under streets and roads running past the buildings, are connected from the main to each building by individual service lines, wherein the main and the service lines all extend below the frost line in the respective areas being served. Each service line is provided with a shut-off valve assembly, typically located near the curb of the street or road, or otherwise near the main supply line, hence the name “curb box”. The assembly generally includes a housing disposed about the valve and a tubular, vertically oriented conduit, typically 4″ to 8″ in diameter, extending from the buried valve housing upwardly to the ground surface, having a cover or lid thereat removably secured to the conduit. This assembly effectively protects the underground valve from the environment and unauthorized access thereto.
To turn the supply of gas or water to an individual building on or off, the cover is removed and a tool, termed a “key”, being a long rod with a slot or fork at its lower extremity, is inserted at the surface opening into the tubular conduit. The key extends downwardly to the head of the valve stem whereat, in theory, the key engages the valve cock and the valve stem is rotated 90° about its vertical axis to turn the gas or water supply to the building off (or on, as the case may be).
Problems associated with conventional curb boxes are well known. Ground in which valves are initially located may be disturbed, such as for backfills in new housing developments. Continuous variations in temperature can cause expansion and contraction of both the ground and the valve and piping. Repeated freezing and thawing can displace the valve substantially out of alignment with the curb box cover and the housing assembly. Soil erosion, water seepage, vehicles driving over the surface above the valve and other, similar forces can all cause the valve to move out of alignment with the access port at the surface, thereby making it difficult or impossible to reach the valve stem with the valve key. If the valve stem is not perfectly upright, it often cannot be opened. When the valve can not be opened by the key, the only available alternative is to excavate, and dig down to the valve itself, locate it, and shut it off. This can be a relatively very expensive operation.
Many prior patents have issued which purportedly address and solve this valve misalignment problem inherently associated with conventional curb boxes. Among these are U.S. Pat. Nos. 5,327,925; 4,572,236; 4,691,733; and the patents set out on the Invention Disclosure Form submitted simultaneously with the original application for this patent. None of these prior patents, nor any of the references cited within them, either discloses or suggests, either alone or in any combination, the features or advantages of the valve key alignment assembly presented hereinbelow.
While each of these prior patents purports to address and solve the curb box valve alignment problem, none provides the advantages, both in achieving mechanical alignment between key and valve stem and extremely low cost, provided by the invention disclosed and claimed herein.